Mold forming device

ABSTRACT

A mold forming device comprising a housing having open ends, a plurality of rods loosely filling the housing and individually adjustable longitudinally therein and means to constrict the inner dimension of the housing to lock the rods against longitudinal adjustment. The rods can be adjusted manually to create a molding surface of desired contour, or may be permitted to slide longitudinally and engage a physical surface, the shape of which is to be duplicated either positively or negatively whereupon the rods are locked so that the housing and the adjusted rods may be used as a forming mold. By laminating the housing, alternate laminations thereof may be relatively offset to effect constriction of the inner dimension of the housing in relation to the rods for locking them against longitudinal adjustment. To effect smoothing the molding surface presented by the ends of the rods, they may be covered by a flexible diaphragm. By having diaphragms at both ends of the housing and providing sealing means for the inner wall of the housing, the space among the rods may be evacuated for pulling the diaphragms at the ends of the rods into contact therewith. The housing and rods may be associated with vacuum-forming or pressure-forming chambers to hot-form sheets of plastic to the mold faces. By providing rods of equal length, whenever they are adjusted to form one molding surface, either male or female, the other ends of the rods form a complementary female or male molding surface respectively.

United States Patent [72] Inventor David H. Humphrey G.P.0. Box 2226,San Juan, P.R. 00903 [21 Appl. No. 805,474 [22] Filed Mar. 10, 1969 [45]Patented Aug. 3, 1971 [$4] MOLD FORMING DEVICE 15 Claims, 12 DrawingFigs.

[52] US. Cl 249/155, 18/5 P [51] Int. Cl. B29c1/00, B29c H16 [50] FieldofSearch 18/5 M, 19 F, 32, 34 M, 42 M, 43, 34 R; 164/172, 173; 249/155;269/287 [56] References Cited UNITED STATES PATENTS 881,912 3/1908Emrick 249/155 X 3,041,669 7/1962 Marshall 18/19 3,319,295 5/1967Jones-Hinton 18/19 Primary Examiner-J. Spencer Overholser AssistantExaminer-Norman E. Lehrer Attomey-Allegretti, Newitt & Witcofi'ABSTRACT: A mold forming device comprising a housing having open ends. aplurality of rods loosely filling the housing and individuallyadjustable longitudinally therein and means to eonstrict the innerdimension of the housing to lock the rods against longitudinaladjustment. The rods can be adjusted manually to create a moldingsurface of desired contour, or may be permitted to slide longitudinallyand engage a physical surface, the shape of which is to be duplicatedeither positively or negatively whereupon the rods are locked so thatthe housing and the adjusted rods may be used as a forming mold. Bylaminating the housing, alternate laminations thereof may be relativelyoffset to effect constriction of the inner dimension of the housing inrelation to the rods for locking them against longitudinal adjustment.

To effect smoothing the molding surface presented by the ends of therods, they may be covered by a flexible diaphragm. By having diaphragmsat both ends of the housing and providing sealing means for 'the innerwall of the housing, the space among the rods may be evacuated forpulling the diaphragms at theiends of the rods into contact therewith.

The housing and rods may be associated with vacuum-forming orpressure-forming chambers to hot-form sheets of plastic to the moldfaces.

By providing rods of equal length, whenever they are adjusted to formone molding surface, either male or female, the other ends of the rodsform a complementary female or male molding surface respectively.

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MOLD FORMING DEVICE Present day methods for mold forming are to firstmake an exact pattern in wood, plaster, clay or the like which isusually a process of cutting material (such as carving a block of wood),or building up material (such as using modeling clay). In either casethere is a lot of work to be done before the shape emerges in its finalform or even in an unrefined final form. Any changes in the shapedesired are time consuming and often cannot be determined until theshape is examined in three dimensions. After the shape is arrived at itis then usually necessary to make a mold form in order to duplicate theshape in small quantities, prior to committing expensive mold makingsuch as required for large production quantities.

One object of my invention is to facilitate the making of patterns andmolds by means of a mold forming device such as I disclose and atechnique for its use which makes possible the creation and/or copyingof a physical contour more quickly and easily than by conventionalmethods such as referred to, and which therefore is of considerablebenefit to industry. The invention also facilitates the making ofpatterns and molds for vacuum-fonning or pressure-forming materials,such as sheet plastic, with a minimum of preparatory work.

Another object is to provide an assembly of housing and a fill" of rodstherein which are longitudinally adjustable so as to form, by the endsof the rods at one end of he housing, a predetermined contour and whichcontour is duplicated in reverse by the other ends of the rods, theadjustments of the rods being accomplished manually and individually orby fitting them to a surface to be duplicated.

Still another object is to provide a housing which is made up oflaminations that can be adjusted laterally relative to each other toconstrict the inner dimension of the housing and thereby lock the rodsin their adjusted positions.

A further object is to provide a design of mold forming device in whichflexible diaphragms span the ends of the rods to smooth out any moldingsurface contours which are dictated by the adjustments of the rods.

Still a further object is to provide for evacuating the space among therods so that air pressure conforms the flexible diaphragms to thecontours presented by the ends of the rods.

An additional object is to provide a clamping ring associated with thehousing for clamping the peripheral portion of a plastic sheet to hehousing, and means to thereafter form the plastic sheet while heated tothe contour of the rods in their adjusted positions by vacuum action inone type of device, or by pressure action in another type.

Yet another object is to provide a mold forming device for formingirregular shapes of expanded plastic in a simple and expeditiousfashion.

BRIEF SUMMARY OF THE INVENTION An open end housing has rods freelyslidable axially therein and is designed to effect constriction of theinternal dimension thereof for locking the rods after they are adjustedto form molding surfaces of any desired contour. The ends of the housingmay be closed in by flexible diaphragms brought into contact with theends of the adjusted rods by forming a vacuum among the rods. A clampingring may be associated with the housing for a clamping a plastic sheetthereover, vacuum or pressure then being used to form the sheet whenheated to the contour presented by the ends of the rods.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of mymold forming device with certain portions thereof broken away and otherportions shown in section to illustrate details;

FIG. 2 is a vertical sectional view on the line 2-2 of FIG. I; and

FIG. 3 is a vertical sectional view on the line 3-3 of FIG. I andillustrates a clamp for the laminations of a housing, which clamp isomitted from FIG. I; 7

FIG. 4 is a sectional view similar to FIG. 2 showing a modification ofmy mold forming device for hot-forming plastic sheets by vacuum, theparts being in an initial position before such forming;

FIG. 5 is a similar view showing the plastic sheet vacuum formed;

FIG. 6 is another modification similar to FIG. 5 showing the plasticsheet pressure formed;

FIG. 7 is a perspective view of a modified mold form of housing andclamping means for rods within the housing;

FIG. 8 is a sectional view of a modified mold forming device for formingirregular shapes by steaming plastic beads retained in a mold cavity; 7

FIG. 9 is a sectional view of a modified mold forming device similar tothat of FIG. 8;

FIG. 10 is a cross-sectional view of a package for an irregular shapedobject;

FIG. 11 is a sectional view of a mold forming device, with theirregular-shaped object of FIG. 10 in place to properly position therods; and

FIG. 12 is a sectional view of the mold forming device of FIG. 11 withsteaming components attached.

On the accompanying drawings I have used the reference character H toindicate in general a housing and R to indicate in general a pluralityof rods therein. FIG. 1 illustrates only some of the rods whereas inactual practice the entire housing is filled with these rods. The rodsare illustrated as round but may be other suitable shapes such assquare, hexagon, etc., or a mixture of shapes.

The rods R loosely fill the interior of the housing l-l so that they maybe individually adjusted longitudinally, each one either depressed orextended with respect to the end face of the housing. One suchadjustment is shown in FIGS. 4 and 5 and another in FIG. 6 to formdifferent contours as will hereinafter appear.

It isvdesirable to provide some means of constricting the innerdimension of the housing H to lock the rods R in position after they areonce adjusted. One way of accomplishing this objective includeslaminating the housing. The housing shown in FIG. I is cylindrical inshape and accordingly may be laminated by constructing it from aplurality of rings 10 alternating with a plurality of rings 12.Obviously when the inner diameters of the rings 10 and 12 are aligned asin FIG. 1, an effective diameter is provided which may be reduced bymisalignment of the inner diameters of the rings 10 and 12.

Such misalignment can be accomplished by pivoting all the rings togetheras by a pivot bolt 14 at one side of the housing and providingprojections 20 and 22 from the rings 10 and 12 at the opposite side ofthe housing which are offset as illus trated when the inner diameters ofthe rings 10 and 12 are in alignment. Then by providing some kind ofclamping means engaging the offset sides of the projections 20 and 22,the tendency upon operation of the clamping means is to align the sidesof the projections, thus moving the inner diameters of the rings 10 and12 to offset relation with each other and therefore clamping positionsas illustrated in FIGS. 5 and 6 for instance. For this purpose a C-clamp16 may be provided having projection engaging equalizer bars 18 and 24and a pressure screw 26.

The housing H and the rods R thus far described may be used withoutdiaphragms 28 and 30 and without a tubular liner 32 which will now bedescribed. The edges of the liner 32 extend over the outer face of theupper ring 10 and the outer face of the lower ring 12, and so do themarginal peripheral edges of the diaphragms 28 and 30, and may beclamped to these particular rings as by bolts 34 and nuts 36. Clampingrings 38 engage the outer surfaces of the diaphragms 28 and 30 tocooperate with the bolts 34 in properly sealing the diaphragms and thetubular liner relative to the ends of the housing H. A vacuum connection40 is provided to communicate with the space among the rods R fordrawing the diaphragms 28 and 30 into contact with the upper and lowerends of the rods respectively when the connection 40 is subjected to theintake of an operating vacuum pump or the like.

In FIGS. 4 and 5, I show a modification wherein the diaphragms 28 and 30and the liner 32 are omitted, and a sheet plastic clamping ring 42 isused to clamp the peripheral margin of a heated plastic sheet 44 againstone end of the housing H, the clamping action being applied according toarrows 46. A vacuum chamber 48 is provided at the other end of thehousing so that when a vacuum is drawn as through a connection 50according to the arrow 52, the hot plastic sheet 44 shown in FIG. 4 willconform to the contour presented by the upper ends of the rods R as inFIG. 5 at Ma.

In FIG. 6 another modification is shown wherein a pressure chamber 54and a pressure connection 56 are provided, the pressure chambercooperating with the clamping ring 42 and thereby operable to pressureform the hot plastic sheet 44 to the shape 44b as distinguished fromvacuum-forming.

In the operation of my mold forming device, since the rods R can beloosened or tightened as desired, they may be moved longitudinally whenloose, and when tightened they assume a fixed relationship that can befirmly maintained. Accordingly, the loosened rods can be adjusted bypushing them in or pulling them out to any shape desired. The shape canbe modified at will. When the desired shape is arrived at, the housingcan be adjusted to tighten or lock the rods. Their ends can then be usedas a male projection, a female cavity or a composite of the two,depending on whether the upper or lower ends of the rods are utilized asthe molding surface. The uneven surface presented by the individual endsof the rods may be smoothed out by the application of plastic materialsuch as plaster, clay or the like, or the diaphragms 28 and 30 may beprovided for this purpose to smooth out and refine the contour or finalshape.

After use, the rods can be returned to their home position shown in FIG.1 and 2 by loosening the housing, and the return of the rods to create aflat surface as illustrated will automatically remove any plasticmaterial that had been added to refine the surface. I

The quality of the surface can be determined by the diameter of the rodsused, and the depth to which the rods can be moved is determined bytheir lengths. The rods may be made of plastic, metal, wood or the like,and their ends may be flat, chamfered, rounded or otherwise modified asfound suitable. The housing can be of any shape, a rectangular shapebeing shown in FIG. 7 wherein a movable wall 56 forms the means forloosening and tightening the rods R, the movement thereof beingindicated by arrows 58.

The method for constricting the inner dimension of the housing H shownin FIGS. 1 and 3 is simple and operable. Thin membranes or diaphragmsare capable of following the intricate shapes that may be created byadjusting the rods. By extracting air from the housing between thediaphragms, a chamber for internal vacuum is created which forces thediaphragms to take on whatever shape results from having adjusted therods. These diaphragms also act as a protective surface for the rods toprotect them from casting or fill-in compounds, and serve to smooth outthe surface irregularities created by the rod end shapes.

As illustrated in FIGS. 5 and 6, my mold forming device may be appliedto vacuum or pressure forming machines for sheet plastic and the like.Vacuum-forming is accomplished by positioning a hot sheet of plastic onthe exposed face of the rods, clamping it around the edge and drawingthe vacuum. The interstices between the rods act as passageways tovacuumize all space within the housing H. Either or both faces of themold form can be used and the convex and concave forms are complementaryto each other and always created simultaneously. Pressure-forming may beaccomplished in a comparable manner except as illustrated in FIG. 6.

Both vacuum as in FIG. 5, and pressure as in FIG. 6, can be usedtogether in order to create greater forming force for the plastic sheet44. Any three-dimensional shape can be copied by pressing the shape intoone end of the housing, making sure that the rods are in contact at allpoints and then creating a mold half or casting half of complementaryshape when using that end of the housing. The other end of the housingis used when the three-dimensional shape referred to is to beduplicated. My mold forming device can be used as a medium for creatingartistic shapes, much as artists now use clay and the like for thatpurpose.

The concept of his invention can also be used to form irregular objectsfrom plastic beads by steaming through the beads confined in the housingor alternatively, plastic containers for retaining irregular shapedobjects can be made in a similar fashion.

Turning to FIGS. 8 and 9, there are shown arrangements for formingirregular objects 0 and 0' respectively, from plastic beads, forexample, polystyrene. In FIG. 8, the rods R are secured in place in eachhousing H, and the housings are clamped together with plastic beads inplace to form the object 0. Steam introduced through the inlet openingin chamber defining member 148 passes through the interstices betweenthe rod R and through the beads to cause them to expand to form theirregular shaped object 0. Member 154 is secured to the upper housing toform a pressure chamber. Steam passing upwardly through the rods R andplastic beads collects in the chamber defined by member 154 and exitsthrough outlet opening 156.

The arrangement of FIG. 9 functions like that of FIG. 8, but forms anobject 0' having a flat surface. This results from use of a singlehousing H having a chamber defining member 148 on one side and a flatpressure cap with vent openings 162 therein secured on the opposite sideof housing H from member 148.

In FIG. 10, there is shown a container comprised of halves 200 and 201for protecting an irregular shaped delicate item 0. The mold formingmechanism for forming the halves 200 and 201 is shown in FIGS. 11 and12. The object O is placed in between the housings H and the rods R arethen positioned as shown in FIG. 11 and locked in place as explainedabove. The housings H are separated and a pressure cap 204 is securedabove the housing H and a chamber defining member 206 is secured to thehousing H as shown in FIG. 12. The beads to be expanded to form thecontainer half are retained in the cavity between the rods R and thepressure cap 204. Steam is injected through opening 208 and passesthrough the interstices between the rods R to expand the beads to formthe container half. The steam vents through suitable vent openings 210in the top of the pressure cap 204. The same steps are repeated with theother housing H in order to form the other container half. If thecontainer halves are the same, then only one housing H need be used.

While there has been described presently preferred embodiments of thepresent invention, it will be understood that the invention is notlimited thereto since it may be otherwise embodied within the scope ofthe following claims.

I claim as my invention:

1. In a mold forming device, a housing having open ends, a plurality ofrods loosely filling said housing and individually adjustablelongitudinally therein, and means to constrict the inner dimension ofsaid housing to lock said rods against such longitudinal adjustment,said housing being laminated laterally of said rods, and alternatelaminations being relatively movable, also laterally, to offset theinner dimensions of said alternate laminations and thereby effect suchlocking.

2. A mold forming device in accordance with claim 1 wherein alternatelaminations are provided with projections offset relative to each otherwhen the inner surfaces of the laminations are aligned, and clamp meansis provided for said projections which, upon operation, tends to alignsaid projections and thereby offset said inner dimensions of saidalternate laminations.

3. A mold forming device in accordance with claim 2 wherein saidprojections are at one side of said housing, and

pivot means is provided through said laminations at apositionsubstantially opposite said projections,

4. A mold forming device in accordance with claim 1 wherein flexiblediaphragms cover the ends of said rods and are sealed to the open endsof said housing.

5. A mold fonning device in accordance with claim 2 wherein flexiblediaphragms span the open ends of said housing and cover the ends of saidrods. I

6. A mold forming device in accordance with claim 3 wherein flexiblediaphragms span the ends of said housings and are sealed relativethereto.

7. A mold forming device in accordance with claim 4 wherein means isprovided to evacuate the space among said rods, between said diaphragrnsand within said housing to draw said diaphragms into intimate contactwith the ends of said rods.

8. A mold forming device in accordance with claim 5 wherein saiddiaphragms have their marginal edges sealed with respect to the openends of said housing, and means is provided to evacuate the space withinsaid housing between said diaphragms to draw the latter into intimatecontact with the ends of said rods.

9. A mold forming device in accordance with claim 6 wherein means isprovided to evacuate the space between said diaphragm: and among saidrods to draw the diaphragms into intimate contact with the ends of saidrods.

10. A mold forming device in accordance with claim 5 wherein a flexibletube is provided lining said housing and exclamping ring is provided fora peripheral portion of the.

plastic sheet with respect to one end of said housing, the other end ofsaid housing having means for sealing the same to establish a vacuumchamber between said last mentioned means, said housing and said plasticsheet.

13. A mold forming device in accordance with claim 3 adapted forpressure-forming a plastic sheet and wherein a clamping ring is providedfor a peripheral portion of the plastic sheet with respect to one end ofsaid housing, means being provided for sealing said clamping ring withrespect to said end of said housing to establish a pressure chamberbetween said last mentioned means, said clamping ring and said plasticsheet.

14. In a mold forming device, a housing having open ends, a plurality ofrods loosely filling said housing and individually adjustablelongitudinally therein, and means to constrict the inner dimension ofsaid housing to lock said rods against such longitudinal adjustment, achamber-defining member secured to one side of said housing and apressure cap secured to said housing, a cavity being defined between therods and the pressure cap for receiving beads to be expanded, and meansfor injecting steam into the housing and through said cavity forexpanding said beads and forming an object conforming to the shape ofthe cavity.

15. In a mold forming device, a housing having open ends, a plurality ofrods loosely filling said housing and individually adjustablelongitudinally therein, and means to constrict the inner dimension ofsaid housing to lock said rods against such longitudinal adjustment, awall means closing the ends of said housing and said rods beingpositioned to form a cavity for receiving beads to be expanded, meansfor injecting steam into said housing for expanding the beads to form anobject corresponding to the shape of the cavity.

1. In a mold forming device, a housing having open ends, a plurality ofrods loosely filling said housing and individually adjustablelongitudinally therein, and means to constrict the inner dimension ofsaid housing to lock said rods against such longitudinal adjustment,said housing being laminated laterally of said rods, and alternatelaminations being relatively movable, also laterally, to offset theinner dimensions of said alternate laminations and thereby effect suchlocking.
 2. A mold forming device in accordance with claim 1 whereinalternate laminations are provided with projections offset relative toeach other when the inner surfaces of the laminations are aligned, andclamp means is provided for said projections which, upon operation,tends to align said projections and thereby offset said inner dimensionsof said alternate laminations.
 3. A mold forming device in accordancewith claim 2 wherein said projections are at one side of said housing,and pivot means is provided through said laminations at a positionsubstantially opposite said projections.
 4. A mold forming device inaccordance with claim 1 wherein flexible diaphragms cover the ends ofsaid rods and are sealed to the open ends of said housing.
 5. A moldforming device in accordance with claim 2 wherein flexible diaphragmsspan the open ends of said housing and cover the ends of said rods.
 6. Amold forming device in accordance with claim 3 wherein flexiblediaphragms span the ends of said housings and are sealed relativethereto.
 7. A mold forming device in accordance with claim 4 whereinmeans is provided to evacuate the space among said rods, between saiddiaphragms and within said housing to draw said diaphragms into intimatecontact with the ends of said rods.
 8. A mold forming device inaccordance with claim 5 wherein said diaphragms have their marginaledges sealed with respect to the open ends of said housing, and means isprovided to evacuate the space within said housing between saiddiaphragms to draw the latter into intimate contact with the ends ofsaid rods.
 9. A mold forming device in accordance with claim 6 whereinmeans is provided to evacuate the space between said diaphragms andamong said rods to draw the diaphragms into intimate contact with theends of said rods.
 10. A mold forming device in accordance with claim 5wherein a flexible tube is provided lining said housing and extendingfrom diaphragm to diaphragm.
 11. A mold forming device in accordancewith claim 8 wherein a flexible tube is provided lining said housing,extending from diaphragm to diaphragm and sealed relative to saidmarginal edges thereof.
 12. A mold forming device in accordance wIthclaim 3 adapted for vacuum-forming a plastic sheet and wherein aclamping ring is provided for a peripheral portion of the plastic sheetwith respect to one end of said housing, the other end of said housinghaving means for sealing the same to establish a vacuum chamber betweensaid last mentioned means, said housing and said plastic sheet.
 13. Amold forming device in accordance with claim 3 adapted forpressure-forming a plastic sheet and wherein a clamping ring is providedfor a peripheral portion of the plastic sheet with respect to one end ofsaid housing, means being provided for sealing said clamping ring withrespect to said end of said housing to establish a pressure chamberbetween said last mentioned means, said clamping ring and said plasticsheet.
 14. In a mold forming device, a housing having open ends, aplurality of rods loosely filling said housing and individuallyadjustable longitudinally therein, and means to constrict the innerdimension of said housing to lock said rods against such longitudinaladjustment, a chamber-defining member secured to one side of saidhousing and a pressure cap secured to said housing, a cavity beingdefined between the rods and the pressure cap for receiving beads to beexpanded, and means for injecting steam into the housing and throughsaid cavity for expanding said beads and forming an object conforming tothe shape of the cavity.
 15. In a mold forming device, a housing havingopen ends, a plurality of rods loosely filling said housing andindividually adjustable longitudinally therein, and means to constrictthe inner dimension of said housing to lock said rods against suchlongitudinal adjustment, a wall means closing the ends of said housingand said rods being positioned to form a cavity for receiving beads tobe expanded, means for injecting steam into said housing for expandingthe beads to form an object corresponding to the shape of the cavity.